majorchamp

I apologize for the vague title but I am not sure how to put into words what happened. I can give you the symptoms I experienced.

Was driving for about 2 hours straight, thru both dry and wet weather. The following symptoms then presented themselves.

1. I see a red BRAKE status show up.
2. Then I see an SBS status show up.
3. Then I see a "visit a shop" message
4. My turn signals don't work.
5. Radio stops working.
6. Windows don't work.
7. Windshield wipers are still moving.
8. I am able to pull into a gas station and park. I proceed to try all the above again...but nothing works.
9. I turn the car off...key still inserted and windshield wipers continue. The CD player area keeps buzzing on/off about every 10 seconds.
10. I remove the key. All the lights stay on. The windshield wipers continue. The CD player keeps buzzing.
11. I can't open the trunk. Windshield wipers keep moving. CD player keeps buzzing.
12. I get under the passenger seat and remove the ground battery cable, thinking I need to essentially force the car to 'reset'.
13. Disconnect...wait 10 seconds, re-connect. Windshield wipers stopped. But CD player keeps making the noise as if it's trying to read a cd/dvd or just a part of the regular startup process..but every 10 seconds.
14. Car won't start. Nothing...turning the key nothing happens.
15. I tried this process a few more times...same result. Same CD player buzzing.
16. Crawled into trunk to open fuse box...thought I could try to remove the fuse for the audio. Found fuse #23 in a picture online (10 amp). Also removed fuse #40 (long green one, 30 amp).

Now...I don't know whether removing those fuses ultimately did anything at all.....because I then decided to disconnect the battery again..but this time wait 30 seconds. So I did...reconnected, and I got the car to start. No errors (besides a check engine light which is ALWAYS on and I don't think related to this issue...as my father in law has run it thru a scanner, think it's spark plug related).

Without the fuses..the radio still played, so maybe those weren't the right fuses or something. I have no clue whether they played a role in the car starting or the 30 second battery disconnect did.

We ended up driving the car home the 2 hours (fun day of worthless driving, basically) and when we got closer to home...1 more thing happened.

I had parked to grab some food and when leaving there was a hill, so I let the car slowly roll down it..and it felt like the brakes were auto kicking in. When I finally got flat and pressed the gas, the car kind of lunged forward, and I ended up seeing a new icon on the status screen. It looks like a car driving over a little bump/hill. I can't find this icon online anywhere so I am not 100% sure.

So based on all these descriptions and symptoms...any clue what is going on?

majorchamp

Maj. Dundee

Remove everything in the spare tire compartment, including the gray mat and you will probably find rain water collected on the floor which has corroded the rear SAM and the tailgate module.

majorchamp

Let me check that out! Thanks

majorchamp

Is this 3 separate steps? i.e; files?

Maj. Dundee

Yes.

majorchamp

That grey mat is basically glued to the metal underside.

These instructions are a little unclear (at least to me).

majorchamp

Ok so I got to it. Honestly...on my particular vehicle...now that I've seen everything, I could have accessed the sam module and popped it out without removing everything.

Do I have to disconnect the battery (under the passenger seat) or anything to disconnect the sam module and pull the black box away so I can inspect it? fwiw...I don't see really any water damage on or around the sam black box. There is one bolt higher up that has corrosion, but nothing down where the black box was sitting (it's in a little metal cage).

PSDCampervan

Removal & exposure of everything to familiarize with what is vulnerable 'below the water line' (mercedes buries much sensitive electronics under floor where most vulnerable) corrosion might build-up on common ground but effect multiple components on icb that appear otherwise undamaged. Those taillight pockets sabotage so many things when they leak. Slather Marine dielectric grease all over ground post & wires might help w/ corrosion there. That icon represents 'off-road driving program' that coordinates 4-ETS, ESP, & ABS to control wheel slippage. Button to activate it just right of hazard light button

majorchamp

Ok so here are some pics. I don't know how to access the other side of the SAM board though.... which is what was facing up when inside the tail light pocket.

https://imgur.com/a/D771qQu

PSDCampervan

I think that whole tray bracket gets energized & two bolts are grounding points but not certain if that's correct. I do know when I was removing RH taillight a wrench came in close proximity to a bolt on SAM that kinda arced but low energy arc. I think it was hot wire post tool almost contacted

Maj. Dundee

From the looks of things, if there is no corrosion on the bottom side, which you posted, then there should be no corrosion on the top side.

To inspect the top side, look at the video.

Maj. Dundee

Anytime you remove an electrical component, the negative cable to the battery should be disconnected.

majorchamp

Good call. Well when I removed it...I "did not" remove the negative battery. But I didn't hit any metal or nuts either. I ended up reconnecting it after looking at it (as best I could) and the car has driven fine. (doesn't mean the issue is fixed..just the car was operational after removing it and reinstalling it)

My father in law works on circuit boards for a living...so I ended up removing it again tonight (this time I removed the neg battery) and gave it to him so he can inspect it under a microscope tomorrow.

Btw...is it possible for some ML 350's to not have an auxillary battery. We replaced the main battery a month ago...but I don't recall seeing an aux battery alongside it.

The next thing that comes to mind is I have a grounding issue. Is there a diagram anywhere that lists the grounding points for this vehicle..so I can look for any rusting or corrosion, especially since I seem to see more issues when it's wet or raining?

Maj. Dundee

All MLs as of 2006 have the Aux. Battery. Its main purpose is to supply 12v to the shift selector so the veh. may be pulled onto a flatbed in case the main battery fails.

majorchamp

I will double check.

If I disconnect my main battery though, I lose all power to the car. You can't do anything else...so the Aux wouldn't help with situations like that?

Maj. Dundee

Even if the main battery was dead, the Aux. Battery will still function.

majorchamp

Thanks. I'm not sure what it is doing. Apparently it won't go dead if the main battery is disconnected for 18 hrs...because well I don't think it is dead.

Btw, had the SAM unit inspected...and nothing appears to to at least visually be wrong with it. It wasn't connected to a SAM monitor to confirm any communication..but there was no water or condensation damage.

Btw, I found 6 grounds under the hood. I don't know how many there are...or where else there are more..but the 6 I could visually see I have attached to this link.

Can you tell me if visually...they look fine? I will have to do a OHM / voltage test soon against them.

https://imgur.com/a/9hW7Y6z
As of right now...the only errors I have on the vehicle is a check engine light which points to

P0016 Crankshaft Position - Camshaft Position Correlation - Bank 1 Sensor A
P0017 Crankshaft Position - Camshaft Position Correlation - Bank 1 Sensor B
P0016 Crankshaft Position - Camshaft Position Correlation - Bank 1 Sensor A
P0017 Crankshaft Position - Camshaft Position Correlation - Bank 1 Sensor B

The others are that it's using the substitute bulbs on the brake (which I've read is a common faulty reading..and requires a wiring harness or something), and it says the

"Marker Lamp front left"
"Brake Lamp, right. Substitute Light on"
"Brake Lamp Left, Substitute Light on"

I also had changed my brakes a while back and started getting a warning about the brakes needing to be checked. We had changed the little sensor that came with them as well...but I guess it didn't take or requires a dealer reset. I don't know.

Maj. Dundee

It is virtually impossible for anyone to say that the grounds are faulty just by looking at photos, unless it is obvious, which they are not.

Does the engine start normally? Does it crank but not start? Or no crank at all? Check fuse #14 in the right side dash fuse box.

Why are you posting codes now, why not when you originally posted?

Please keep answers short and to the point.

majorchamp

Grounds: Got it.

Ever since the original issue with all the electrical gremlins in my OP, the car has been driving and behaving fine. The check engine light is one we have had for years. Given the car has driven fine all this time with that light on, I did not think it was related to the electrical problems surfacing, which seems to occur when conditions are wet. When we drove the vehicle home after getting it started up again after the electrical gremlins in my OP, it was a 2 hour trip (so 4-5 hrs on the road that day), we did drive thru rain again but the electrical issues did not reoccur. The issue is intermittent.

I also did not remember which codes they were at the time of posting, and had a scan done at Autozone the other day. I will have to see if the 305 degrees crankshaft and the alignment in those 2 holes where the sensors go line up or not..but we have changed the sensors before and the codes come back.

The brake light substitute warnings have been off and on for 1-2 years.

I'm trying to answer your questions and provide context at the same time. I am currently driving the vehicle as well, as it is operating fine for the time being.

Maj. Dundee

Almost all of your posts are misleading and I cannot figure out what you are doing. I cannot provide any further help with your problems.

majorchamp

I don't see how they are misleading.

My OP (original post) states all the issues I faced this past Sunday. After disconnecting the battery for 30 seconds, I reconnected it and got the warnings, alerts, etc.. to disappear. The car started again..and I ended up driving it home instead of getting it towed 2+ hrs away.

The rest of my posts are simply things I've noticed over time. But I've NEVER had the car in such a condition like I had it on Sunday, where the wipers kept going after the key was removed, the cd player buzzing every 10 seconds, the car locks not working, the trunk not opening, etc.

I've done a visual check of the right rear taillight enclosure for moisture, water. I've inspected the SAM module for water damage, I've provided pics along the way for this stuff.

I'm trying to be helpful, not misleading.